To reduce production costs by reducing the number of components and assembling man-hours, and to improve gas-liquid separating performance of a refrigerant.

In this accumulator 1 including a bottomed cylinder-shaped body 3 opened at its top end, and a header 2 sealing the opening end of the body 3, and separating the refrigerant flowing in from a refrigerant inflow hole 15, into gas and liquid in the body 3, the header 2 includes a header body 11 having the refrigerant inflow hole 15, and a separating section 12 disposed at a lower part of the header body 11 and separating the refrigerant flowing in from the refrigerant inflow hole 15 into gas and liquid, and the header body 11 and the separating section 12 are integrally formed. Further, the refrigerant inflow hole 15 is formed vertically downward from the top face of the header body 11, and preferably disposed concentrically with the separating section 12.